Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of the first state in a sequence for a displayscreen or portion thereof with transitional graphical user interfaceshowing our new design;

FIG. 2 is a front view of a second state thereof;

FIG. 3 is a front view of a third state thereof;

FIG. 4 is a front view of a fourth state thereof;

FIG. 5 is a front view of a fifth state thereof; and,

FIG. 6A-FIG. 6B is a front view of a sixth state thereof.

The outermost broken line rectangle illustrates a display screen orportion thereof and forms no part of the claimed design. The remainingbroken lines, including all text, illustrate portions of the graphicaluser interface that form no part of the claimed design. The appearanceof the transitional graphical user interface sequentially transitionsbetween the images shown in FIGS. 1-6. The process or period in whichone image transitions to another forms no part of the claimed design.

CLAIM The ornamental design for a display screen or portion thereof withtransitional graphical user interface, as shown and described.